With reference to the prior art in the field it has been shown that fixation of meniscus trausmas like ruptures and lesions by suturing with absorbable sutures gives better results than the removal of traumatized meniscal tissue (see e.g. N. A. Palmeri, T. F. Winters, A. E. Joiner and T. Evans, "The Development and Testing of the Arthroscopic Meniscal Staple", Arthroscopy, Vol. 5, No. 2, 1989, p. 156 (Ref. 1)). However, arthroscopic suturing is a complicated technique where risks for the patient are significant because of danger to vessels and nerves. Therefore, the desire of surgeons has been already for a long time to have an absorbable meniscus lesion fixation device like a staple or fastener which should have the advantages of absorbable suturing techniques but which could be more rapidly used and without complications of suture technique.
Several research groups have tried to develop absorbable meniscus lesion fixation devices like clamps or the like. However, the various demands upon such a device are high. It must be strong enough to maintain the good contact of lesion tissues after operation so that rapid healing occurs. The device must retain its strength long enough for good healing. It must be biocompatible and it must be absorbed without causing complications which should prevent the healing of lesion. Additionally, the installation of the device should be easy and rapid and should cause minimum operational trauma. Because of those high demands, a satisfactory, absorbable meniscus lesion fixation device has not been developed yet. Palmeri et al. reported in Ref. 1 the development of a method of meniscal repair using arthroscopically applied absorbable fasteners. However, the reported method was complicated because the final design used cannulation of the staple for needle-guided placement. Additionally staple fracture, migration and articular abrasion was found.
With regard to implants known in this field, reference is made to U.S. Pat. No. 4,873,976 which discloses an arrow-like implant particularly for repair surgery of meniscal rupture. However, the arrow-like implant according to this publication has the disadvantage that particularly its stem is shaped as a plate in a way that the direction of the main plane of the plate is perpendicular to the longitudinal direction of the body. Because of this fact, it is particularly difficult to install the implant, because the installation channel to be used in connection with installing the implant must be formed to have the cross-sectional shape of the stem; it is difficult to guide the implant in the installation channel, because the guiding effect is substantially brought upon the stem only. Furthermore, due to the structure of the stem, it causes mechanical irritation and abrasion of the tissue particularly when placed in connection with the meniscus, because the stem is usually left protruding to a high degree from the outer surface of the meniscus.